The present invention relates to a magnetic sensor for use in brushless direct current motors and position detecting devices.
The demand for a highly sensitive magnetic sensor is rising in order to keep in time with the development of miniatuarization and low pressure operation of brushless direct current motors and of position detecting devices.
Conventionally, in order to make a highly sensitive magnetic sensor, Hall effect devices made of semi conductor material such as gallium arsenic or indium phosphorous and the like which have high mobility characteristics have been utilized for highly sensitive magnetic sensors.
By utilizing semi conductor materials which have high mobility characteristics, there is a limit in improving the magnetic sensitivity. Also, when integrating comparators and other logic circuits in addition to the Hall effect device onto one chip, silicon is the most utilizable material as the material for magnetic sensors. However, the Hall effect device made of silicon has a defect that its magnetic sensitivity is low.